Bearing oil scavenger



March 22, 1960 F. w. HoELTJE 2,929,663

. BEARING on. scAvENGER Filed nay 2a. 1957 2 sheets-snee: 1

A TTOPN March 22, 1960 F. w` HOELTJE 2,929,663

BEARING OIL SCAVENGER IN VEN T 0R.

ATTOENY BEARING OIL SCAVENGER Frederick W. Hoeltje, Indianapolis, Ind., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application May 28, 1957, Serial No. 660,500

2 Claims. (Cl. 308-187) This invention concerns generally oil sealing arrangements between relatively rotatable shaft assemblies. It is particularly concerned with the seals for oil circulated by centrifugal action to lubricate bearings between the shafts themselves and the shafts and shaft housings.

By way of example, it is well known that in two-spool engines of the jet type there are mounted for rotation in the engine housing two concentric shafts, both of which may rotate relative to the engine housing and also relative to each other. In such engines there are normally areas adjacent the bearings which, if not properly sealed olf from the bearings, will be undesirably contaminated by the oil used to lubricate these bearings. This results in substantial losses of lubricating oil and also may be dangerous if the oil in such areas should become vaporized and then be ignited. It will be appreciated that since the oil is to be distributed radially to lubricate the bearings from an axial location the lubricating oil must pass through the areas between the spaced shafts and between the outer shaft and housing before Vbeing returned to a suitable sump. These relatively wide radial areas present severe oil seal problems which heretofore have not been satisfactorily solved.

The present invention has been proposed to obviate the above diiiiculties by provision of unique composite oil slingers and seals which cooperate with the shafts, housing and bearings to confine the passage of the oil radially in a relatively narrow annular section including a sump from which the oil may be scavenged to be circulated again.

For a more complete understanding of the invention and the objects thereof reference may be had to the accompanying detailed description and the drawings, in which:

Fig. 1 is a view in elevation of a portion of a two-spool jet engine with parts broken away and in section embodying the invention.

Fig. 2 is an enlarged detail View in perspective of a portion of one of the unique composite seal and oil slingers between the outer shaft and housing of Fig. 1 used to conne the oil into a relatively small annular area and prevent its leaking into areas which would result in the loss of oil and also the danger of the oil vaporizing and upon ignition exploding.

Fig. 3 is another perspective view of a portion of an oil slinger and seal similar to that shown in Fig. 2 except that the vanes on the slinger are arranged to direct the oil in an opposite axial direction.

Fig. 4 is a view in perspective of a portion of the unique composite oil slinger and seal located between the inner shaft and the outer shaft. l

Referring now to the drawings and particularly to Fig. l, that portion of the engine shown comprises an outer engine housing 2 having formed therein by the walls 4, 6, 8, 10, 12 and 14, respectively, an annular cavity indicated generally by a numeral 16. Secured inside the housing 2 and extending thereabout is aradial bearing support 18 in which is secured by threaded cap 20 a 2,929,663 Patented Mar. 22, 1960 roller bearing set 22. Roller bearing set 22 is convenf tional and includes the usual inner and outer races and the annularly spaced plurality of roller bearings. Journaled for rotation in bearing set 22 is an outer shaft assembly 24 which at one end thereof has connected thereto a turbine wheel 26. Pressed inside the shaft assembly 24 is a second roller bearing set 28 which, except for the fact that it is smaller, is similar to bearing set 22. Bearing set 28 has journaled for rotation therein and in outer shaft 24a concentrically located inner shaft assembly 30 which is connected between a forward compressor section and a rearward turbine section, neither of which are shown. Concentrically located within the inner shaft assembly 30 and supported thereby is an axially extending oil conducting conduit 32 which rotates with shaft 30. The conduit 32 is connected to a suitable oil pressure source (not shown) and conducts oil from the pressure source to a series of radial passages 34 and 36, respectively, which, due to rotation of the parts includingv conduit 32 and passageways 34, 36, will cause the oil to be centrifuged radially outwardly away from the axis of the shaftv assemblies 24 and 30. Passageways 34 lead to ports 38 on the outer periphery of shaft assembly 30, which are in communication with an annular area 40 between the inner and outer shaft assemblies. The inner surface of the outer shaft assembly 24 in the area 40 is formed with a trough 42 which collects the oil centrifuged outwardly through the ports 38. Since, however, shaft 24 is also normally turning, the oil collected in trough 42 will be centrifuged through passages 44 in shaft 24 to ports 46 which jet the oil parallel to the shaft axes through the bearing set 22 so as to lubricate the bearing. The oil centrifuged through the passage 36 likewise is jetted axially through aport 48 into the bearing 28 so `as to lubricate that bearing.

The oil after lubricating bearings 22 and 28 must be collected and cooled so that it may again be circulated through the bearings. For such purpose a sump 50 is provided in the lower part of the cavity 16 when viewing the drawing, which sump is connected by the conducting means 52 with a scavenging pump (not shown).

To prevent the oil used to lubricate bearings 22 and 28 from passing into undesirable locations such as those indicated at 54, 5,6 and 58 and to assure that the oil once lubrieationof bearings 22 and 28 has been completed is collected, the unique composite oil slingers andseals have been provided. The iirst of such seals is indicated generally by a numeral 60 and is vlocated between the inner and outer shafts 24 and 30 and mounted on shaft 30 and fastened at its one end so that it rotates therewith. This seal and oil slinger 60, the details of which are best observed in Fig. 4, comprises a more or less axially extending conical portion 62 to the right of which, as viewed in the drawings, are a plurality of annularly spaced radially extending diagonally positioned vanes 64 which are substantially located in an annular chamber 66, formed by the seal 60, the Vbearing 28 and a member 68 forming a part of shaft assembly 24. To the right of the vanes 64, as viewed in Fig. l, are a series of radial anges formed on a cylindrical portion 69 of the seal 60 which sealingly engage the member 68 so as to prevent the ow of oil therepast into the area 56 from chamber 66. The vanes 64 are so arranged that any oil from the chamber 66 which tends to flow from chamber 66 past the vanes 64 and the anges of the seal into the area 56 will be pumped back into the chamber 66 or toward the bearing 28. Since shaft 30 is rotating along with the composite oil slinger and seal 60, the oil in chamber 66 will be centrifuged upwardly through a series of openings 70 in member 68 and through openings 72 and 74 which lead through the outer shaft assembly 24 to its outer periphery or exterior.

` ing ang/esysealngly engaging annular member .67..to

. Llthrough the openings 70, Y

bearing 222 to commingle w1thetheoil usedlto lubricate a Y Y a Y Y Y Y,

As V'previously mentioned, Aoil is also centrifuged outwardly and jetted through the bearing assembly 22.

oil is confined to the areas 7 6, 78 on opposite sides of the bearing 22 by a pair of Vcomposite oil slinger seals indicated generally by 'numerals 180 `rid.,82;Y respectively. Composite slingerrand seal80 (in addition zto Fignfl sefe also Fig. 2) is provided with an .axially extending .cylinrical sectionV 84 having outwardly extending radial sealvide'arseal'fbetween thehousing 2 `and, arear 58 tending -toV prevent oil from inding its'wayintojt'he :area Seal assembly 82 (seeFigs. 1 and 3') is providediwitha similar axiallyext'ending cylindrical portion ''vwhch is .also

provided with radially extending .anges sealinglyY .engaging anmilar member 14, Ytendingto prevent oil from nding vits WayrQmad'acen the "bearing 22 past Ythe Vseal intoV the area 54,"F1`he composite oilfslin'ger and-seal Y ffrss'emllies .'80 and 82, it'rwill be observed, aref mounted for rotationfon the assembly l2li. 'It twill fbenoted -thatseals F80 'fand 82 each vare,-provile'd with-a -ra'dial 1in- 'Wnrdly .jfacingitrough 788 and i90, respectively; to-twhich'the oilnneither 'side ofthe bearing `assembly 22 will be-Ycen- -tifuged' by `reason yo'f -the rotatingaction Yof the pieces.

The oil ,collected in trough 90alsoincludes theil ffrom ladjacent the bearing 28 vandchamber66 whichhas passed 72 and -74 into the areaadjacent 'bearing Y22.V Seal'82 Von itslouterperipheryradially-outboard'ofvthef trough l80 isalso -provided with a plurality of annlarly 1 spaced radial diagonal :vanes V2971. Connecting the area between the vanes Vand theitroughsSS and 90 are pro- 4 for cooling and recirculating. The seals Aare arranged so as to prevent the dow of oil .therepast and to further posiisY aplural-ityV of -annnlarlyspaced ports 92. 'y f hese ports jet the oil :from trough V88;;into a'trough-like area-94 which f 3lea'ds to thesump 50. If,however,l any-'oil should-tend *to leakpastthe vanes 91 intothe area 96 andfpast the fsealportion-84, the vanes-91 are -arranged so-that they bearing l through 'tively pump toward the center of the annular area and the bearings any oil whichtendsto leak past the seals.

Y l claim:

1. A shaft arrangement comprising; in combination, a housing dening Ya chamber, a first bearing supported in the chamber, a hollow outer shaft rotatablyY mounted in the rst bearing, a second bearing VVrnountedwithin the Outer .shaft .an inaershaft monntsd in .the Second bearing. means for `supplying lubricating oil to thebearings, a viirst labyrinth seal betweenthe outer shaftand 'the housing, a rst oil slinger mounted on and rotatable with vthe outer shaft between thefrrst bearing andthe 'rsts'eaL' ascavenge oil receiver adjacent thle'rrst oil vslinger within the cham ber, a second labyrinth seal betweenthe shafts, and a sec- 'l ond oil slinger mounted on and'rotatable with the inner shaft between the secondbearing and the second seal,

the Vsaid l-oil slingers hayingvanes extending outwardly therefrom ,and directed helicallyof .the. slhaft in .such

direction to ,urge oil .towardlthe hearing radially #from the .-shaft, .the .outer shaft having an opening lfor discharge Aof .oil .therethrough from .the second .`slinger,

theopening communicating kwith a space :between the rst .bearing and .rst slinger, and the first slinger having an opening-therethrough for discharge of oil from the second the :first slinger. linto the scavenge oil receiver. Y Y i f V2. A shaft arrangementcomprising, "in combination, .a housing -deining Va chamber,` a`lrst bearing supported in the. chamber, a hollow outer.shaft rotatably.. mounted in the,rstbearing, ya Asecondi?bearing .mounted within the Y nouter shaft, an inner shaft mounted inthesecondbearing,

meansfor supplying lubricating .oiLtoth'e bearings, `a scavenge oilre'ceiver-withinvthe chamber, a labyrinth seal *between* the shafts, an oil slinger mounted on and rotatablewththeyinnervshaft between the .second bearing and the seal,-the said-oil slingerahaving vanesfextending outwardly'therefrom; and directed helically of the shaft in -suchdirection vas to urge Yoilv toward the bearing and Y radially from the shaft, the outer shaftthaving an opening ,for discharge of oil therethroughfrom theslinger com- -municating with. the scavengebil A receiver. Y Y

:'fromthe center' of-.theV assembly radially; outward torpror- Y Y `iride-the stepped-bearingassembly with lubrication while fconning the-oil to av relatively narrow annular area which `'henleads .to the-sumpwherethe oil maybe scavenged 

